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chondroid syringoma
Wednesday 25 July 2012
Malignant Cutaneous Mixed Tumor
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Definition: Cutaneous mixed tumor (chondroid syringoma) is the cutaneous counterpart of pleomorphic adenoma of salivary glands, comprised of both epithelial and mesenchymal components. Malignant transformation is exceptionally rare, with only a few cases reported.
Mixed tumor/chondroid syringoma which is characterized by PLAG1 gene rearrangement.
Images
Chondroid syringoma
- https://twitter.com/Levelsx5/status/782390463701651460
- https://twitter.com/pepeheffernan/status/1324795846819532809
Malignant mixed tumor arising in chondroid syringoma : perineural invasion, mitosis
Differential diagnosis
salivary mixed tumors
malignant chondroid syringoma
apocrine tumors
- apocrine mixed tumor: has characteristic decapitation secretion
- other adnexal tumors with apocrine differentiation
- cutaneous chondroma: lacks the epithelial and myoepithelial elements
mixed tumors
* malignant mixed tumor: necrosis, infiltrative growth, marked pleomorphism and greater cellularity
metastatic carcinoma: can often be distinguished based on immunohistochemistry and cytologic features of malignancy
parachordoma: rare, no true ducts, actin negative, presence of physalliferous cells, arises adjacent to tendon and synovium in extremities
- often considered a variant of myoepithelioma
collagenous spherulosis: more common in breast, lumina contain dense eosinophilic secretion, no biphasic appearance
hidradenoma papilliferum: no chondroid matrix, not biphasic
myopeithelioma / adenomyoepithelioma of the skin: more common on extremities, myoepithelial areas should predominate, lacks luminal epithelial cells, negative for cytokeratin and CEA
See also
cutaneous apocrine tumors
mixed tumors
syringoma
Open references
Myoepithelial neoplasms of soft tissue: an updated review of the clinicopathologic, immunophenotypic, and genetic features. Jo VY, Fletcher CD. Head Neck Pathol. 2015 Mar;9(1):32-8. doi : 10.1007/s12105-015-0618-0
PMID: 25804378 (Free)